Lightly spray an unheated large saucepan with no-stick spray.
Add the onions, sausage and garlic.
Cook over medium heat until the sausage is browned, stirring occasionally.
Stir in the broth, lentils, tomatoes (with juices), Worcestershire sauce, oregano, pepper, cumin and bay leaf.
Bring to a boil, then reduce the heat.
Cover and simmer for 15 minutes.
Add the carrots, celery and spinach.
Return to a boil, then reduce the heat.
Cover and simmer about 20 minutes or until the lentils and vegetables are tender.
Remove and discard the bay leaf before serving.